tnameserv Man page

tnameserv Java IDL and RMI-IIOP Tools tnameserv

NAME

tnameserv – Interface Definition Language (IDL).

SYNOPSIS

tnameserve -ORBInitialPort [ nameserverport ]

-ORBInitialPort nameserverport
The initial port where the naming service listens for the
bootstrap protocol used to implement the ORB
resolve_initial_references and list_initial_references methods.

DESCRIPTION

Java IDL includes the Object Request Broker Daemon (ORBD). ORBD is a
daemon process that contains a Bootstrap Service, a Transient Naming
Service, a Persistent Naming Service, and a Server Manager. The Java
IDL tutorials all use ORBD, but you can substitute the tnameserv
command for the orbd command in any of the examples that use a
Transient Naming Service.

See orbd or Naming Service at
http://docs.oracle.com/javase/8/docs/technotes/guides/idl/jidlNaming.html

The CORBA Common Object Services (COS) Naming Service provides a tree-
structure directory for object references similar to a file system that
provides a directory structure for files. The Transient Naming Service
provided with Java IDL, tnameserv, is a simple implementation of the
COS Naming Service specification.

Object references are stored in the name space by name and each object
reference-name pair is called a name binding. Name bindings can be
organized under naming contexts. Naming contexts are name bindings and
serve the same organizational function as a file system subdirectory.
All bindings are stored under the initial naming context. The initial
naming context is the only persistent binding in the name space. The
rest of the name space is lost when the Java IDL naming service process
stops and restarts.

For an applet or application to use COS naming, its ORB must know the
port of a host running a naming service or have access to an initial
naming context string for that naming service. The naming service can
either be the Java IDL naming service or another COS-compliant naming
service.

START THE NAMING SERVICE
You must start the Java IDL naming service before an application or
applet that uses its naming service. Installation of the Java IDL
product creates a script (Oracle Solaris: tnameserv) or executable file
(Windows: tnameserv.exe) that starts the Java IDL naming service. Start
the naming service so it runs in the background.

If you do not specify otherwise, then the Java IDL naming service
listens on port 900 for the bootstrap protocol used to implement the
ORB resolve_initial_references and list_initial_references methods, as
follows:

tnameserv -ORBInitialPort nameserverport&

If you do not specify the name server port, then port 900 is used by
default. When running Oracle Solaris software, you must become the root
user to start a process on a port below 1024. For this reason, it is
recommended that you use a port number greater than or equal to 1024.
To specify a different port, for example, 1050, and to run the naming
service in the background, from a UNIX command shell, enter:

tnameserv -ORBInitialPort 1050&

From an MS-DOS system prompt (Windows), enter:

start tnameserv -ORBInitialPort 1050

Clients of the name server must be made aware of the new port number.
Do this by setting the org.omg.CORBA.ORBInitialPort property to the new
port number when you create the ORB object.

RUN THE SERVER AND CLIENT ON DIFFERENT HOSTS
In most of the Java IDL and RMI-IIOP tutorials, the naming service,
server, and client are all running on the development machine. In real-
world deployment, the client and server probably run on different host
machines from the Naming Service.

For the client and server to find the Naming Service, they must be made
aware of the port number and host on which the naming service is
running. Do this by setting the org.omg.CORBA.ORBInitialPort and
org.omg.CORBA.ORBInitialHost properties in the client and server files
to the machine name and port number on which the Naming Service is
running. An example of this is shown in Getting Started Using RMI-IIOP
at http://docs.oracle.com/javase/8/docs/technotes/guides/rmi-
iiop/rmiiiopexample.html

You could also use the command-line options -ORBInitialPort
nameserverport# and -ORBInitialHost nameserverhostname to tell the
client and server where to find the naming service. For one example of
doing this using the command-line option, see Java IDL: The Hello World
Example on Two Machines at
http://docs.oracle.com/javase/8/docs/technotes/guides/idl/tutorial/jidl2machines.html

For example, suppose the Transient Naming Service, tnameserv is running
on port 1050 on host nameserverhost. The client is running on host
clienthost, and the server is running on host serverhost.

Start tnameserv on the host nameserverhost:

tnameserv -ORBInitialPort 1050

Start the server on the serverhost:

java Server -ORBInitialPort 1050 -ORBInitialHost nameserverhost

Start the client on the clienthost:

java Client -ORBInitialPort 1050 -ORBInitialHost nameserverhost

STOP THE NAMING SERVICE
To stop the Java IDL naming service, use the relevant operating system
command, such as kill for a Unix process or Ctrl+C for a Windows
process. The naming service continues to wait for invocations until it
is explicitly shut down. Note that names registered with the Java IDL
naming service disappear when the service is terminated.

OPTIONS

-Joption
Passes option to the Java Virtual Machine, where option is one
of the options described on the reference page for the Java
application launcher. For example, -J-Xms48m sets the startup
memory to 48 MB. See java.

EXAMPLES
ADD OBJECTS TO THE NAME SPACE
The following example shows how to add names to the name space. It is a
self-contained Transient Naming Service client that creates the
following simple tree.

Initial Naming Context
plans
Personal
calendar
schedule

In this example, plans is an object reference and Personal is a naming
context that contains two object references: calendar and schedule.

import java.util.Properties;
import org.omg.CORBA.*;
import org.omg.CosNaming.*;
public class NameClient {
public static void main(String args[]) {
try {

In Start the Naming Service, the nameserver was started on port 1050.
The following code ensures that the client program is aware of this
port number.

Properties props = new Properties();
props.put(“org.omg.CORBA.ORBInitialPort”, “1050”);
ORB orb = ORB.init(args, props);

This code obtains the initial naming context and assigns it to ctx. The
second line copies ctx into a dummy object reference objref that is
attached to various names and added into the name space.

NamingContext ctx =
NamingContextHelper.narrow(
orb.resolve_initial_references(“NameService”));
NamingContext objref = ctx;

This code creates a name plans of type text and binds it to the dummy
object reference. plans is then added under the initial naming context
using the rebind method. The rebind method enables you to run this
program over and over again without getting the exceptions from using
the bind method.

NameComponent nc1 = new NameComponent(“plans”, “text”);
NameComponent[] name1 = {nc1};
ctx.rebind(name1, objref);
System.out.println(“plans rebind successful!”);

This code creates a naming context called Personal of type directory.
The resulting object reference, ctx2, is bound to the name and added
under the initial naming context.

NameComponent nc2 = new NameComponent(“Personal”, “directory”);
NameComponent[] name2 = {nc2};
NamingContext ctx2 = ctx.bind_new_context(name2);
System.out.println(“new naming context added..”);

The remainder of the code binds the dummy object reference using the
names schedule and calendar under the Personal naming context (ctx2).

NameComponent nc3 = new NameComponent(“schedule”, “text”);
NameComponent[] name3 = {nc3};
ctx2.rebind(name3, objref);
System.out.println(“schedule rebind successful!”);
NameComponent nc4 = new NameComponent(“calender”, “text”);
NameComponent[] name4 = {nc4};
ctx2.rebind(name4, objref);
System.out.println(“calender rebind successful!”);
} catch (Exception e) {
e.printStackTrace(System.err);
}
}
}

BROWSING THE NAME SPACE
The following sample program shoes how to browse the name space.

import java.util.Properties;
import org.omg.CORBA.*;
import org.omg.CosNaming.*;
public class NameClientList {
public static void main(String args[]) {
try {

In Start the Naming Service, the nameserver was started on port 1050.
The following code ensures that the client program is aware of this
port number.

Properties props = new Properties();
props.put(“org.omg.CORBA.ORBInitialPort”, “1050”);
ORB orb = ORB.init(args, props);

The following code obtains the initial naming context.

NamingContext nc =
NamingContextHelper.narrow(
orb.resolve_initial_references(“NameService”));

The list method lists the bindings in the naming context. In this case,
up to 1000 bindings from the initial naming context will be returned in
the BindingListHolder; any remaining bindings are returned in the
BindingIteratorHolder.

BindingListHolder bl = new BindingListHolder();
BindingIteratorHolder blIt= new BindingIteratorHolder();
nc.list(1000, bl, blIt);

This code gets the array of bindings out of the returned
BindingListHolder. If there are no bindings, then the program ends.

Binding bindings[] = bl.value;
if (bindings.length == 0) return;

The remainder of the code loops through the bindings and prints outs
the names.

for (int i=0; i < bindings.length; i++) { // get the object reference for each binding org.omg.CORBA.Object obj = nc.resolve(bindings[i].binding_name); String objStr = orb.object_to_string(obj); int lastIx = bindings[i].binding_name.length-1; // check to see if this is a naming context if (bindings[i].binding_type == BindingType.ncontext) { System.out.println("Context: " + bindings[i].binding_name[lastIx].id); } else { System.out.println("Object: " + bindings[i].binding_name[lastIx].id); } } } catch (Exception e) { e.printStackTrace(System.err) } } }

SEE ALSO

· orbd

JDK 8 21 November 2013 tnameserv